Multiple myeloma (MM) represents prototypical disease model to study tumor heterogeneity due to the high frequency of intra-clonal diversity within malignant clone of plasma cells (PC) in the bone marrow.
To better understand the myeloma heterogeneity within complex myeloma pathophysiology, we perform large-scale mass cytometry (CyTOF) analysis in the cohort of bone marrow samples from MM patients (n=188) compared to 10 age-matched healthy donors.
We design a pipeline for deep characterization of PC within the immune ecosystem of the myeloma microenvironment enrolling bone marrow of MGUS, smoldering MM, newly diagnosed and relapsed or relapsed/refractory MM patients.
To evaluate intra and inter-tumor heterogeneity by profiling of PC clusters, we revealed spectrum of PC sub-clonal clusters with phenotypic and signaling variations and abundance supported the idea of sub-clonal heterogeneity within MM tumor.
To further investigate the genetic heterogeneity and clonal evolution characterizing MGUS, smoldering MM, newly diagnosed and relapsed or relapsed/refractory MM patients DNA from 322 and RNA from 144 primary isolated plasma cells of patients diagnosed with MGUS, SMM, NDMM and RRMM were analyzed by targeted NGS (and additionally tested by WES sequencing) and the real-time PCR method using Bio-Rad's Tier 1 and Tier 2 Multiple Myeloma expression arrays, respectively. Moreover, comprehensive analysis of B cell lymphopoiesis reveals various immunophenotyping aberrancies and signaling modulations with frequency assessment in MM patients.
The impact of immune landscape of the tumor microenvironment in MM by high-dimensional approaches revealed significant immune dysfunction that will lead to more effective therapeutic strategies to improve patient outcome. This study will provide the rational for prediction of MM patient status/prognosis and design of targeted therapy in MM on personalized bases.